package cn.adkii.springframework.beans.factory.support;

import cn.adkii.springframework.beans.BeansException;
import cn.adkii.springframework.beans.PropertyValue;
import cn.adkii.springframework.beans.PropertyValues;
import cn.adkii.springframework.beans.factory.config.BeanDefinition;
import cn.adkii.springframework.beans.factory.config.BeanReference;
import cn.hutool.core.bean.BeanUtil;

import java.lang.reflect.Constructor;

/**
 * @author malingdi
 * @description
 * @date 2023/11/23 10:40
 */
public abstract class AbstractAutowireCapableBeanFactory extends AbstractBeanFactory{
    private InstantiationStrategy instantiationStrategy = new CglibSubclassingInstantiationStrategy();

    public InstantiationStrategy getInstantiationStrategy() {
        return instantiationStrategy;
    }

    public void setInstantiationStrategy(InstantiationStrategy instantiationStrategy) {
        this.instantiationStrategy = instantiationStrategy;
    }

    @Override
    protected Object createBean(String beanName, BeanDefinition beanDefinition, Object[] args) throws BeansException {
        Object bean = null;
        try{
            bean = createBeanInstance(beanDefinition, beanName, args);
            // 给bean填充属性
            applyPropertyValues(beanName, bean, beanDefinition);
        }catch (Exception e){
            throw new BeansException("Instantiation of bean failed", e);
        }
        addSingleton(beanName, bean);
        return bean;
    }

    protected Object createBeanInstance(BeanDefinition beanDefinition, String beanName, Object[] args){
        Constructor constructorToUse = null;
        Class<?> beanClass = beanDefinition.getBeanClass();
        Constructor<?>[] declaredConstructors = beanClass.getDeclaredConstructors();
        for (Constructor ctor: declaredConstructors){
            if (null != args && ctor.getParameterTypes().length == args.length){
                constructorToUse = ctor;
                break;
            }
        }
        return getInstantiationStrategy().instantiate(beanDefinition, beanName, constructorToUse, args);
    }

    /**
     * bean 属性填充
     */
    protected void applyPropertyValues(String beanName, Object bean, BeanDefinition beanDefinition){
        try {
            PropertyValues propertyValues = beanDefinition.getPropertyValues();
            for (PropertyValue propertyValue : propertyValues.getPropertyValues()){
                String name = propertyValue.getName();
                Object value = propertyValue.getValue();
                if (value instanceof BeanReference){
                    // A:依赖B  获取B的实例化
                    BeanReference beanReference = (BeanReference) value;
                    value = getBean(beanReference.getBeanName());
                }
                // 属性填充
                BeanUtil.setFieldValue(bean, name, value);
            }
        }catch (Exception e){
            throw new BeansException("Error setting property values:" + beanName);
        }
    }
}
